Rep. Lamar Smith, R-Texas, said the committee is conducting an investigation into a series of grants “worth millions of dollars” into nonprofits established by Shukla and by what Smith’s letter calls “an egregious use of taxpayer money.”

Watchdog.org left two messages with Shukla’s office Monday and Tuesday, but did not receive a response. Two voicemail messages were also left for his attorney that went unreturned.

Shukla made headlines last month when, along with 19 others, he wrote a letter to President Obama, Attorney General Loretta Lynch and the head of the White House Office of Science and Technology Policy “strongly” supporting using federal racketeering laws to investigate those in the private or public sector who work with the fossil fuel industry to “undermine climate science.”

“If this information is accurate, it raises serious questions about Dr. Shukla’s use of grant money,” Smith’s Monday letter said.

Shukla was the lead signatory of the letter calling on what’s commonly called the RICO statute as part of investigations regarding climate change.

After the resulting criticism, a number of those who signed the letter said the racketeering law would not be aimed at other scientists but against “corporations in the fossil fuel industry and their supporters” who have “knowingly deceived the American people about the risks of climate change.”

In his only comments to the media since the story broke, Shukla on Oct. 7 told the website Inside Climate News,”I signed this letter as a private citizen on personal time, urging action on climate change, and I have been shocked by the reaction … Any allegations of inappropriate behavior are untrue.”

Last week, Watchdog.org reported that Smith has sent letters to NASA, the National Oceanic and Atmospheric Administration and the National Science Foundation requesting “all documents and communications” made to Shukla and IGES from those respective agencies as part of the committee’s investigation.

NASA, NOAA and NSF each gave Skukla IGES grant money.

In a news release Monday, Smith said he was not focusing on the increasingly polarized debate among climate scientists, but on the potential questions surrounding Skukla’s finances.

“It appears that grants provided to IGES are not serving the intended purpose of providing services to the public,” Smith said. “Instead, taxpayers appear to be picking up the tab for excessive salaries, nepotism, questionable money transfers and political activity while receiving little or no benefit. The public expects non-profit organizations that receive taxpayer money to exercise responsible stewardship of their tax dollars.”

Smith’s office said none of the other 20 scientists who signed the letter to Obama have been contacted by the committee’s investigation.

The office of the Science Committee’s ranking member, Rep. Eddie Bernie Johnson, D-Texas, did not have any comment about the pending investigation. “We don’t yet have enough information on this investigation to comment,” Kristin Kopshever, administrative and communications director, said in an email to Watchdog.org.